FR2619549A1 - MACHINE FOR THE FILM WRAPPING OF CYLINDRICAL PRODUCTS - Google Patents

Abstract

This machine makes it possible to package cylindrical products 5 in a heat-sealable film 43 coming from a roll 23, 24 or 25, by means of a fixed lower double welding jaw 7 and a mobile upper double welding jaw 10. vertically and provided with a cutting tool 13. According to the invention, the machine is equipped to perform an automatic film change, in order to be able to package products 5 of different length. To this end, a deflector 37 integral with the movable jaw 10 is in particular provided for guiding the new film 44 of different width, which is unwound after winding the film 43 previously used.

Description

Wrapping machine

of cylindrical products.

  The present invention relates to a machine for wrapping cylindrical products in film; this invention relates, more particularly, to a machine for packaging cylindrical parts or articles, or cylindrical packages formed by several parts or articles, in a film welded on itself in the direction

  longitudinal of the product to be wrapped, and forming a sort of enclosed sheath

rant this product.

  We already know, by French patent n 2219060 (SOBREAL),

  a process for producing this type of packaging, which consists of

  sentially: - - to unroll and stretch a heat-sealable film coming from at least one roll, - to bring the product to be wrapped against the stretched film, - to push the product perpendicular to the film so that it carries with it this film, which then wraps around the product, - to perform on the film two parallel welds, the first weld joining the ends of the portion of film which envelops the product, and the second weld joining the portions of film located on both sides else of the portion that wraps the product, and

  -to cut the film between the two welds.

  The film is thus wound all around the product to be packaged, and after the welds and the cut have been made, the product can be removed with the portion of film which envelops it. The remaining film, again welded on itself to form a continuous sheet, can then be

  unrolled and stretched to pack the following product.

  French patent no. 2219060 also describes a machine implementing the method mentioned above. The machine in question mainly comprises: - a feeder for feeding the products to be packaged, - one or more rolls of heat-sealable film placed at the top of the machine, - a double fixed lower welding jaw, - a double jaw upper welding, vertically movable, a cutting tool associated with one of the welding jaws,

  - a tether on which the film passes during unrolling -

of one of the rollers,

  - a chute located below the lower welding jaw

  and used to pull the end of the film formed by small

  lost portions, reunited with each wrapping operation by the se-

  welding, and - means for receiving and supporting the products being packaged. When using this kind of machine, it may be necessary to package cylindrical products of various lengths. If the

  machine is equipped, at its upper part, with several rolls of film

  It is easy to foresee that these rollers are formed by films.

  cules of different widths, suitable for example for packaging products with two or three different lengths. However, when changing the length of the products to be packaged, the passage from one film of given width to another film of different width still poses difficulties: Due to the operation of the machine in question, the passage

  from one film to another, requires that the film previously

  rolled up and used is rolled up again, and the new film

  to use, previously on standby and fully wound, is unwound.

  Currently, this is done manually, and

  it represents an intervention that is costly in time and in manpower.

  Until now, the problem of automating film change has not been solved, due in particular to the difficulties encountered

  for guiding the free end of a film to be unrolled or rolled up.

  Taking into account the lightness of the film, a free unrolling, without guidance, is to be excluded because a simple draft would deform and deflect

  the film, thus preventing its arrival at a specific point on the machine.

  One could imagine guiding devices by means of grippers

  sant the film, but such devices would be a very complicated and expensive implementation, especially since we should then provide clamps of variable spacing to adapt to different widths of

film.

  The object of the present invention is to provide a machine of the

  kind considered here, perfected so as to be able to ensure automa-

  change of film, eliminating any human intervention for this operation and satisfactorily resolving the

  film guide problems.

  For this purpose, in the machine according to the invention for the wrapping of cylindrical products under film, the double welding jaws and the cutting tool are provided so as to be able to produce either two parallel welds separated by a cut, in order to allow the use of the same film for the wrapping of the following product,

  either a single weld and a cut, in order to free the film to allow

  be its winding and the unfolding of another film, in particular

  of different width, before wrapping the next product.

  When two successive products have the same length, the machine is used in a known manner, by carrying out a double seal and a cut of the film at the end of the wrapping of the first product and before the wrapping of the next product. On the other hand, if two successive products have different lengths, a single weld and a cut of the film are made at the end of the wrapping of the first product. The film is therefore no longer joined, by a second weld, to the lost part engaged in the chute. Thus, this film is free and it can be rolled up, after which another film of width

  different, adapted to the length of the following product, can be unrolled.

  According to a preferred embodiment of the invention, the upper double welding jaw, movable vertically, carries a deflector for guiding the film; this jaw and its deflector are lowered during a change of film, so as to accompany the descent of the new film, which can thus be guided by

  precisely without risking being deflected by a draft.

  To facilitate the winding of the previously used film, and the unwinding of the new film, the invention also provides:

  - a deflector flap is arranged between the charger of the ma-

  china and the fixed lower welding jaw, this deflector flap being tilted during a film change; and

  - that the tethering comprises movable rollers which are rele-

  so as to allow free passage of rolled up film and

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  unfolded, during a change of film.

  Advantageously, the rolls of film are carried by a chassis mounted to move horizontally at the top of the machine,

  a motor being provided in this part for the winding control / -

  unwinding of any of the rolls of film.

  Preferably, the machine also includes means for detecting

  tion of the length of the cylindrical products arriving on its loader, means of automatic selection of one of the rolls of film as a function of the length of the products, and means of

  automatic control of the film change sequence.

  The machine thus equipped allows the film used for wrapping the products to be changed automatically, whenever necessary due to a change in the length of the products.

  to be packaged, or even each time a product arrives, if the machine needs to

  lopper products whose lengths alternate. The change of film

  is carried out quickly, with precise guidance guaranteeing the ar-

  new film rolled up between the rollers of the puller

  falls. The additional equipment of the machine, necessary for the implementation of the invention, remains limited and increases its cost only in a small proportion. Finally, it should be noted that the proposed guiding principle (deflector integral with the movable welding jaw) makes the operation of this machine entirely independent of the particular widths of the films and of the positioning of the rollers.

of film.

  In any case, the invention will be better understood using the

  description which follows, with reference to the appended schematic drawing represented

  feeling, by way of nonlimiting example, an embodiment of this machine for wrapping cylindrical products in film Figure I is a front view of a machine according to the invention Figure 2 is a side view of the machine of figure 1, illustrating a first step of operation during a change of film

  Figures 3 and 4 are side views similar to Figure 2, illus-

  trant two other operating stages; Figure 5 is a detail view, on an enlarged scale, showing

  more particularly the two welding jaws.

  The machine shown in the various figures comprises a frame 1, formed of pillars 2 and crosspieces 3. At the front of the frame I is provided a loading table 4, on which are brought one by one the cylindrical products 5 to be packaged. A movable deflector flap 6 is arranged between the loading table 4 and the working area of the machine, located between

the pillars 2.

  A fixed welding jaw 7 is arranged horizontally, substantially at the level of the loading table 4. As shown more particularly in FIG. 5, the fixed welding jaw 7 comprises two welding electrodes 8 and 9, facing upwards, which are parallel

  to each other and separated from each other by a small distance.

  Above the fixed welding jaw 7, a jaw is provided.

  mobile welding choir 10, also horizontal. As indicated

  more particularly FIG. 5, the mobile welding jaw 10 comprises

  takes two welding electrodes 11 and 12, facing down, parallel to each other and arranged so as to cooperate, respectively, with the two electrodes 8 and 9 of the fixed jaw 7. A movable cutting tool 13 is provided between the two electrodes 11 and 12 of the welding jaw

mobile 10.

  This movable welding jaw 10 can be moved vertically-

  ment, as indicated by the double arrow 14 in FIG. 2, its displacement

  in the direction of ascent or descent is controlled by a motor 15 driving a winch which winds or unwinds cables 16

  to which the movable welding jaw 10 is suspended.

  Behind the vertical plane containing the two jaws of support

  Dage 7 and 10, a tilting roller table 17 is provided, receiving and supporting the cylindrical products 5 during packaging. The rear table 17 can be moved vertically under the control of a motor 18 driving a winch which winds or unwinds cables 19 to which this table is suspended 17. The tilting of the rear table 17 is

  controlled by means of at least one pneumatic cylinder 20.

  Vertical guide rails, not shown, mounted on the pillars 2 of the frame 1, guide the movable welding jaw

  and the rear table 17, in their vertical displacements.

  The upper part of the frame I has horizontal beams

26 1 9549

  21, oriented from front to back, on which is movably mounted a frame 22 serving as a support for three rolls of heat-sealable film 23, 24 and 25, intended for the packaging of products 5. Each roll of film 23, 24 or 25 rests on a pair of carrier cylinders 26, with horizontal axes. A motor 27 is provided for the control of winding / unwinding of the film rolls 23, 24 and 25. The assembly formed by the movable frame 22 and by the film rolls 23, 24 and 25 can be moved horizontally, d '' back to back or back to front (see arrows

  28 and 29 of Figure 2), under the control of a cylinder not shown.

  The frame I carries, at its upper part, a double deflector 30 for the film in use, coming from one of the three rollers 23, 24 and 25. This film then passes over a fixture 31, comprising two fixed rollers 32 and 33, and two movable rollers 34 and 35 carried by pivoting arms 36 of angled shape, the pivoting movement

  arms 36 being controlled by means not shown.

  Another deflector 37 is mounted integral with the movable welding jaw 10, the film in use passing between this

jaw 10 and deflector 37.

  Finally, there is provided, below the fixed welding jaw 7, a tie rod 38 formed by two rollers 39 and 40, making it possible to pinch the film between them, one of the rollers 39 being carried by

  pivoting arms 41 maneuverable by means of a jack 42.

  When the machine is running, the length of the cylindrical products

  ques 5 which arrive on the loading table 4 is detected automatically-

  ment, and depending on the width of these products 5, there is an automatic selection of one of the three rolls of film 23, 24 and 25, of which

  the width corresponds to the length of the products 5.

  If two or more products 5 appearing successively are of the same length, they will be wrapped in the same film 43, unwound from one of the rollers 23, 24 and 25. Each cylindrical product is pushed perpendicular to the film 43 which initially forms a screen extending between the fitting 31 and the chute 38, and this product thus reaches the rear table 17, while the movable welding jaw 10 is lowered. A portion of film 43a then wraps the product 5, by winding over a full turn, the ends of this portion of film 43a being joined and finally clamped between the two welding jaws 7 and 10, as shown in FIG. 5 . The

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2'619549

  corresponding electrodes 8, 9 and 11, 12 then make two parallel welds on the film 43 between which the cutting tool 13 cuts the film 43. One of the welds joins the two ends

  of the portion of film 43a which envelops the product 5, and cuts it

  carried out by tool 13 allows this packaged product to be removed. The other weld joins the portion of film 43b, then located above the welding jaws 7 and 10, with the portion of film 43c located below these jaws and engaged in the chute 38. The initial screen formed by the film 43 is thus reconstituted and, after raising the movable jaw 10, the machine can wrap the following product in the same

film 43.

  We now consider the case where, after wrapping a cylindrical product 5 in the film 43, the next product which reaches the loading table 4 is of a different length from the previous one

  and must therefore be wrapped in another film. For example-

  ple, the previous product 5 was wrapped in the film 43a unwinding

  lant of the extreme roller 23 (see FIG. 2), while the following product must be wrapped in the film 44 coming from the middle roller 24 (see

  figure 3) or the other extreme roller 25 (see figure 4).

  In such a case, at the end of the wrapping of the preceding product 5, the corresponding electrodes 9 and 12 are supplied to join the two ends of the portion of film 43b surrounding this product, and the film 43 is cut. by means of the tool 13, but the two other corresponding electrodes 8 and 11 are not supplied, unlike the case described above. Thus, the two portions of film 43b and 43c, located respectively above and below the jaws

  7 and 10, are not met; the film portion 43b therefore remains free.

  One then proceeds to the opening of the chute 38, by displacement of the roller 39 by means of the jack 42, as well as to the tilting of the deflector flap 6. The movable rollers 34 and 35 of the tether 31 are also raised rotating the arms 36. The motor 27 is then controlled so as to raise the film 43 previously used, by

  winding it again on the roller 23.

  It then becomes possible to unroll the other film 44, of different width. If this film 44 comes from the middle roller 24, it is not necessary to move the frame 22 (case of FIG. 3). On the contrary, if the new film 44 to be unrolled comes from the extreme roller 25,

  the chassis 22 must be moved beforehand (case of FIG. 4).

  To unwind the film 44, the motor 27 is controlled to

  such that the free end of this film 44 descends, crossing

  sant the double deflector 30 then passing between the rollers of the

  rage 31. The free end of the film 44 thus reaches between the

  mobile welding nozzle 10 and the deflector 37 secured to this jaw, which was previously raised. The unwinding of the film 44 continuing, the movable jaw 10 and the deflector 37 are lowered

  so as to accompany the descent of the free end of this pel-

  when the movable jaw 10 comes against the fixed jaw 7, the film 44 continues to descend further, passing between the

  deflector flap 6 tilted and fixed jaw 7, then between the two wheels

  the separated parts 39 and 40 of the chute 38 (see FIG. 4). The deflector flap 6 and the chute 38 are then closed. The movable jaw 10 is

  ascent and lashing 31 is returned to its initial position.

  The new film 44 thus forms a screen held at its lower part by the chute 38, and the machine is ready to operate in order to wrap in this film 44 the first product.

5 which presents itself.

  The film change sequence, which has just been described, takes place entirely automatically, with control means.

  appropriate. In particular, a photoelectric cell can detect the ar-

  riveted in the high position of the film 43 which is rolled up, a time delay

  to ensure that this film 43 is fully

  rolled up, before starting to unroll the other film 44.

  It goes without saying that the invention is not limited to the only embodiment of this machine for wrapping cylindrical products under film which has been described above, by way of example; she

  on the contrary, embraces all the variants respecting the same principle.

  cipe, whatever the constructive details, particularly with regard to

  identifies the means for controlling the moving parts, and whatever

  the nature and exact form of the wrapped "cylindrical" products.

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Claims (4)

Claims I - Machine for wrapping cylindrical products with film, of the type comprising: - a loader (4) for supplying the products (5) to be packaged, - several rolls of heat-sealable film (23,24,25 ) placed at the top of the machine, - a double fixed lower welding jaw (7), - a double upper welding jaw (10), vertically movable, - a cutting tool (13) associated with the one of the welding jaws (7,10), - a fixture (31) on which the film (43,44) passes during the course of one of the rollers (23,24,25), - a chute (39) located below the lower welding jaw (7), and serving to pull the end of the film (43,44), and - means (17) for receiving and supporting the products (5) in packaging course, characterized in that the double welding jaws (7,10) and the cutting tool (13) are provided so that two parallel welds separated by a cut can be produced , in order to allow the use of the same film (43) for the wrapping of the next product (5), that is to say a single weld and a cut, in order to release the film (43) to allow its winding and unwinding another film (44), in particular of different width, before the wrapping of the next product (5).   2 - Machine according to claim 1, characterized in that the upper double welding jaw (10), movable vertically, carries a deflector (37) for guiding the film, this jaw (10) and its deflector (37) being lowered when changing film,   so as to accompany the descent of the new film (44).   3 - Machine according to claim I or 2, characterized in that a movable deflector flap (6) is disposed between the loader (4) and the fixed lower welding jaw (7), this deflector flap (6) being   toggled during a film change.   4 - Machine according to any one of claims I to 3,   characterized in that the tether (31) comprises movable rollers (34, 35) which are liftable so as to allow free passage of the   films (43,44) rolled up and unwound, during a change of film.   - Machine according to any one of Claims 1 to 4,   characterized in that the rolls of film (23,24,25) are carried by a frame (22) mounted horizontally movable at the top   of the machine, a motor (27) being provided in this part for the com   winding / unwinding command of any of the film rolls (23,24,25).   6 - Machine according to any one of claims I to 5,   characterized in that it also includes self-detection means   length of the cylindrical products (5) arriving on its load   geur (4), means for automatically selecting one of the rolls of film (23,24,25) according to the length of the products (5), and   means for automatic control of the sequence of change of pel-   shakes. 7 - Machine according to claim 6, characterized in that there is provided a photoelectric cell for detecting the arrival in position   top of the rolled up film (43) when changing the film.